MySQL子查询错误：SQLSTATE [42S21]：列已存在：1060重复列名'id'

Question

我努力让以下MySQL声明发挥作用。

SELECT ItemGroup.users_id,ItemGroup.comments_id,ItemGroup.uploads_id,ItemGroup.posts_id, 
                Comment.id,Comment.uploads_id,
                CommentUpload.id,
                Upload.id,
                Post.id
                FROM items AS ItemGroup
                LEFT JOIN (
                    SELECT Comment.id, Comment.uploads_id, CommentUpload.id, CommentUpload.uuid
                    FROM comments As Comment
                    INNER JOIN (
                        SELECT CommentUpload.id, CommentUpload.uuid
                        FROM uploads AS CommentUpload
                        ) CommentUpload ON CommentUpload.id = Comment.uploads_id
                    GROUP BY Comment.uploads_id
                ) Comment ON Comment.id = ItemGroup.comments_id
                LEFT JOIN (
                    SELECT Upload.id
                    FROM uploads AS Upload
                    ) Upload ON Upload.id = ItemGroup.uploads_id
                LEFT JOIN (
                    SELECT Post.id
                    FROM posts AS Post
                    ) Post ON Post.id = ItemGroup.posts_id
                WHERE ItemGroup.users_id = {$__cakeID__$}
                AND (
                Comment.id IS NOT NULL 
                OR Upload.id IS NOT NULL 
                OR Post.id IS NOT NULL
                )
                LIMIT 0 , 300

我试图找到与评论相关的上传但是它正在抛出SQLSTATE [42S21]：列已经存在：1060重复列名＆＃39; id＆＃39;。

我确定它有点小，但我无法找到我做错的事情，我真的很感激一些帮助。

感谢您的时间！

亚历

Answer 1

您无法为具有相同别名FROM comments As Comment和GROUP BY Comment.uploads_id) Comment的两个表命名，例如使用Comment_A和Comment_B。